Odor control material

ABSTRACT

An absorbent article is disclosed for absorbing bodily fluids which has incorporated therein an odor control material for decreasing bodily odor which material comprises a zeolite having an average particle size (distribution by weight in sieve analysis) of at least 200 um. The zeolite may optionally be mixed with an absorbent gelling material and/or activated carbon.

FIELD OF INVENTION

This invention relates to an odour control material, and in particularto an absorbent article for absorbing bodily fluids comprising the odourcontrol material and to the use of a zeolite as an odour controlmaterial.

BACKGROUND OF THE INVENTION

Absorbent articles are designed to be worn by humans to absorb bodilyfluids, such as urine, menstrual fluid and perspiration, etc. Examplesof absorbent articles include sanitary napkins, pantiliners, disposablediapers, incontinence pads, tampons and the like.

In use, the absorbent articles are known to acquire a variety ofcompounds, for example volatile fatty acids (e.g. isovaleric acid),ammonia, amines (e.g. triethylamine), sulphur containing compounds (e.g.mercaptans, sulphides), alcohols, ketones and aldehydes (e.g.furaldehyde) which release unpleasant odours. These compounds may bepresent in the bodily fluid or may be produced by fermentation once thebodily fluid is absorbed into the pad. In addition bodily fluids cancontain microorganisms that can also generate malodorous by products.Unpleasant odours which emanate from absorbent pads when in use may makethe wearer feel self conscious.

Various odour controlling materials have been disclosed. In particular,certain zeolitic materials are becoming known for their odourcontrolling properties. Zeolitic materials are generally quite safe andhave been found to control many odours associated with bodily fluids.

Zeolites as odour controlling materials have been disclosed in the art,as is discussed below.

U.S. Pat. No. 4,304,675 discloses a powdered carpet treatmentcomposition containing a natural or synthetic zeolite, which zeolite ispreferably zeolite A. The zeolite is said to have a particle size of 3.5μm and in which about 4% of the particles have a micrometer size ofgreater than 10 micrometers.

U.S. Pat. No. 4,525,410 discloses a fibre article having antibacterialproperties comprising zeolitic particles retaining therein at least onemetal ion having bactericidal property and a mixed fibre assembly. Thezeolite has a low framework ratio of SiO₂ /Al₂ O₃. The zeolite has theions Ag⁺, Cu²⁺ or Zn²⁺ associated therewith.

WO 81/01643 discloses the removal of ammonia (and other toxic orpotentially toxic nitrogenous irritants) from diapers by incorporatinginto the diaper an inorganic aluminosilicate zeolite ammonium ionexchange material. The zeolite is said to be synthetic or natural andthe only zeolite exemplified is naturally occurring clinophlolite.

U.S. Pat. No. 4,826,497 discloses fibrous absorbent articles intendedfor the absorption of bodily fluids comprising synthetic zeolitesprepared using an organic templating agent prepared in siliceous form inwhich at least about 90% of the framework tetrahedral units are SiO₂tetrahedra, which has pore diameters of at least 5.5 Å and has acapacity for absorbed water of not greater than 10% under standardconditions. The framework ratio of SiO₂ /Al₂ O₃ of the synthetic zeoliteis high. The Examples all utilize steam treated zeolite Y or silicalite.

WO 91/11977 discloses a method for decreasing odours associated withbodily fluids comprising contacting said fluids with an odourcontrolling amount of an intermediate framework SiO₂ /AlO₂ zeolite.

In the prior art disclosures all the zeolite odour controlling materialstend to be in the form of very small dusty particles which are difficultto handle on a commercial scale; they generally have a size of <5 μm.Such materials tend to be blown or vacuumed up from absorbent structuresmoving at high speeds (500-600 items/minute) used on modern catamenialor diaper manufacturing lines and this is a problem.

A system has been suggested to overcome this problem and in particularWO 91/12030 discloses combining particulate carbon odour controllingagents with white coloured zeolite or other "masking materials", usingbinder materials. This system is however expensive and the effectivenessof the odour control material can be reduced.

The object of the present invention is thus to provide an absorbentarticle providing odour control using an material which can be handledeasily in production of an absorbent article, which has good odourcontrolling properties and is not expensive.

SUMMARY OF THE INVENTION

It has been surprisingly found that zeolites in a form having an averageparticle size (distribution by weight in sieve analysis) of at least 200μm act as a very efficient odour control material and can be easilyhandled.

Accordingly the present invention provides an absorbent article havingincorporated therein an odour control material for decreasing odoursassociated with bodily fluids which material comprises a zeolite havingan average particle size (distribution by weight in sieve analysis) ofat least 200 μm.

The present invention also provides an odour control composition fordecreasing bodily odour associated with bodily fluids which compositioncomprises a zeolite having an average particle size (distribution byweight in sieve analysis as hereinbefore defined) of at least 200 μmtogether with an absorbent gelling material (AGM) and/or activatedcarbon.

Preferably the average particle size of the zeolite is from 200 to 500μm, more preferably from 300 μm to 400 μm.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be illustrated with reference to the detaileddescription and examples taken in conjunction with the accompanyingFigures.

FIG. 1 shows a cross sectional view of a commercially availablepantiliner is namely the Always Comfort Pantiliner by Procter & GambleCompany.

FIG. 2 shows a cross sectional view of a pantiliner having the odourcontrol material incorporated therein.

FIG. 3 shows a cross sectional view of a pantiliner having an absorbentcore comprising three cellulose tissue layers, the odour controlmaterial being incorporated between the first and second tissue layers.

FIG. 4 shows a cross sectional view of a pantiliner having an absorbentcore comprising three cellulose tissue layers, the odour controlmaterial being incorporated between the second and third tissue layers.

FIG. 5 shows the results of comparative example A.

FIG. 6 shows the results of comparative example B.

FIG. 7 shows the results of comparative example C.

DETAILED DESCRIPTION OF THE INVENTION

The sieve analysis method as mentioned above is performed as follows:

The particle size distribution and the average particle size of amaterial (zeolites, activated carbon, AGM etc.) is determined by amechanical sieve shaker method using an electromagnetic sieve shakerFritsch ® Analysette 3 with six analytical sieves (20, 30, 40, 70, 100and 140 Mesh, respectively corresponding to 850, 600, 425, 212, 150 and106 μm) and one sieve pan. The selected sieves are nested with thecoarsest sieve at the top and the solid pan at the bottom, then the testsample (100 g of material) is placed on the top sieve and the nest isclosed with a cover. The shaker is operated for 15 minutes continuouslywith an amplitude of vibrations of 1 mm and finally, after thecompletion of the agitation, the material retained on each sieve isweighed separately. The material which has passed through the finestsieve into the pan is also weighed.

These weights and the weight of the original test sample are used tocalculate the particle size distribution and the average particle sizeof the test sample. The particle size distribution is obtained by simplydividing the weight of the material retained on each sieve by the totalweight of the test sample. In order to get the average particle size thepercentage retained on each sieve is calculated by dividing the "totalweight coarser" than that sieve by the total weight of the test sample.The total weight coarser includes the material retained on thatparticular sieve plus all material on all coarser sieves. Thiscumulative percentage represents the total percentage of the test samplecoarser than the aperture of that particular sieve.

The data is plotted on a sieve analysis graph where the abscissarepresents the sieve sizes (on a logarithmic scale) and the ordinate thepercentages retained (on a linear scale). By interpolation on the sieveanalysis graph the sieve size corresponding to a percentage of 50%retained can be evaluated, and this size is taken as the averageparticle size of the sample.

The zeolite may be used as such or in a form which has been granulatedwith a binder.

The zeolite used in the present invention is a known material. Whilesome naturally occurring zeolites meet the objectives of the inventionsynthetic zeolites of the types available in commerce are generallypreferred.

In general terms, zeolites comprise an aluminate/silicate framework,with associated cations, M, providing overall electrical neutrality.Empirically, the zeolite framework can be represent as

    x AlO.sub.2.y SiO.sub.2

and the electrical neutral zeolite as

    x/n M.x AlO.sub.2.y SiO.sub.2.z H.sub.2 O

wherein: x and y are each integers, M is a cation and n is the charge onthe cation. As noted by the empirical formula, zeolites may alsocomprise water of hydration (z H₂ O). Reference to the literature willillustrate that M can be a wide variety of cations, e.g. Na⁺, K⁺, NH₄ ⁺,alkylammonium, heavy metals and the like. The practice of the presentinvention does not require any particular selection of cation;accordingly the sodium ion is convenient and preferred.

The manufacture of zeolite materials of the type used in the practice ofthis invention is well-known, and reference can be made to theliterature for typical synthetic procedures. For example attention isdirected to synthetic procedures described in the following referencetexts: ZEOLITE SYNTHESIS, ACS Symposium Series 398, Eds. M. L. Occelliand H. E. Robson (1989) pages 2-7; ZEOLITE MOLECULAR SIEVES, Structure,Chemistry and Use, by D. W. Breck, John Wiley & Sons (1974) pages245-250, 313-314 and 348-352; MODERN APPLICATIONS OF MOLECULAR SIEVEZEOLITES, Ph.D. Dissertation of S. M. Kuznicki, U. of Utah (1980),available from University Microfilms International, Ann Arbor, Michigan,pages 2-8.

The zeolite used in the present invention preferably has less than 10%,preferably less than 7% by weight of particles having a size less than100 μm.

The zeolite preferably has a low framework ratio, in particular it has aframework ratio of SiO₂ /Al₂ O₃ of not more than 4:1, preferably notmore than 2:1.

The zeolite preferably has a pore diameter of from 0.30 to 0.55 nm,preferably from 0.4 to 0.45 nm.

The zeolite is preferably a zeolite A and more preferably a Na⁺ zeoliteA.

The zeolite preferably is a compound based on a zeolite A which isgranulated with sodium sulphate and carboxy methyl cellulose (CMC). Thiszeolite is sold by Degussa AG under the trade name Wessalith CS. Thezeolite may also be granulated with bentonite and/or polyacrylate and issold under the trade name Wessalith by Degussa AG. Although any zeolitehaving an average particle size of at least 200 μm may be used in thepractice of the invention.

The odour control material may also comprise other conventionalcompounds, for example activated carbon, other zeolites;

charcoal, antimicrobial agents, ionic absorbents, such as an absorbentgelling material (AGM) or known odour control agents in powder form.

It is essential that the conventional compounds are also in powder formwhich powders conventionally have average particle sizes of at least 200μm, preferably from 200 to 500 μm thus enabling the odour controlmaterial to be easily handled and dosed with the conventional compound.

Preferably the odour control material also comprises AGM or activatedcarbon, more preferably it comprises AGM and activated carbon. Thematerial may also comprise AGM and bentonite. The AGM, activated carbonand bentonite all have odour controlling properties. The quantity ofAGM, activated carbon and bentonite used with the odour control materialmay readily be determined by the skilled person dependant on theabsorbent article in question.

It has been found that from 2 to 70% of the total weight of theabsorbent article should be made up of the odour control material, whichmaterial may be zeolite alone or zeolite together with AGM and/oractivated carbon. For products having a weight of approximately 2 g apreferred quantity of odour control material is 0.7 g which quantityprovides odour control. For 0.7 g of odour control material it ispreferable to have about 31% by weight of zeolite, AGM and about 26% byweight activated carbon. Another preferred odour control material has0.4 g zeolite and 0.3 g (about 43% by weight) absorbent gellingmaterial.

The absorbent article may be a sanitary napkin, a pantiliner, adisposable diaper, an incontinence pad, tampon or the like. According toone aspect of the invention the absorbent article is a pantiliner.According to another aspect of the invention the absorbent article is asanitary napkin.

The weight of the odour control material which may be used in theabsorbent article can be readily determined by the skilled personbearing in mind the size of the absorbent article in question. Forexample a suitable quantity of odour control material which may be usedin a pantiliner is from 0.05 to 0.8 g, preferably the quantity is from0.1 to 0.5 g.

Preferably AGM is included in the article together with the odourcontrol material used in the present invention. The quantity of AGMwhich may be added may be readily determined by the skilled person foreach absorbent article. Preferably 0.05 to 0.7 g and more preferablyfrom 0.1 to 0.5 g of AGM is added to a pantiliner.

The odour control material may be incorporated into the article bymethods known in the art, for example layered on or into the core of theabsorbent material or mixed within the fibres of the absorbent core. Theodour control material is preferably incorporated between two layers ofcellulose tissue, optionally the material may be bonded between twocellulose tissue layers with, for example, a hot melt adhesive or anysuitable bonding system.

More preferably AGM and activated carbon are included in the articletogether with the odour control material used in the present invention.The AGM is included in the amounts shown above and the activated carbonis included in amounts of from 0.05 to 0.7 g, more preferably from 0.1to 0.5 g in the pantiliner.

More preferably the odour control material is incorporated in a layeredstructure in accordance with the disclosure of WO 94/01069 or TO 93A001028. TO 93A 001028 describes a layered structure substantially asdescribed in WO 94/01069 with the exception that TO 93A 001028 comprisesa much higher quantity of AGM in the intermediate layer which is betweenthe fibrous layers, namely in an amount exceeding 120 g/m². In additionthe intermediate layer in TO 93A 001028 also comprises thermoplasticmaterial, which when heated, melts and bonds the first and second layerstogether with the intermediate layers and thus AGM between them. Thebridges which form the bond points between the fibrous layers involveparticles of AGM as well as particles of thermoplastic material. Theabsorbent capacity of the AGM is unaffected by bonding.

An absorbent article, namely a pantiliner which is an exemplaryembodiment of an article into which the odour control material may beincorporated, is shown in cross section in FIGS. 1 to 4.

The pantiliner may be of any shape known in the art, for example,rectangular, hour glass, winged, etc.

As shown in FIGS. 1 and 2 pantiliner 1 comprises a liquid pervioustopsheet 2, a secondary top sheet 3, an absorbent core 4 and a liquidimpervious backsheet 5. It is not, however, intended that the pantilinershould be limited to embodiments comprising all such elements.Additional elements known to the skilled person may also be included inthe pantiliner.

The topsheets 2 and 3 are liquid permeable and, when pantiliner 1 is inuse, are in close proximity to the skin of the user. The topsheet 2 and3 are compliant, soft feeling and non-irritating to the user's skin. Itcan be made from any of the conventional materials for this type of use.Non-limiting examples of suitable materials that can be utilized as thetopsheets 2 and 3 are woven and non-woven polyester, polypropylene,nylon and rayon and formed thermoplastic films. Formed films arepreferred for topsheet 2. Suitable formed films are described in U.S.Pat. No. 4,324,246, U.S. Pat. No. 4,342,314, U.S. Pat. No. 4,341,217 andU.S. Pat. No. 4,463,045. Secondary topsheet 3 is preferably a non-woven,more preferably an air through non-woven with a basis weight of 21 g/m²,the non-woven being as disclosed in WO 93/09744.

The formed films are preferred for topsheet 2 because they are perviousto liquids and yet non-absorbent. Thus, the surface of the formed film,which is in contact with the body, remains dry and is more comfortableto the wearer. The topsheet may be constituted by the covering structurefor sanitary products described in EP-A-0 207 904. Preferably thetopsheet 2 is made of polyethylene perforated film (24.5 g/m²).

The inner surface of secondary topsheet 3 may be secured in contactingrelation to absorbent core 4. This contacting relationship results inliquid penetrating the topsheet 3 faster than if it were not in contactwith absorbent core 4. Topsheet 3 can be maintained in contact with theabsorbent core 4 by applying adhesive, preferably in spaced limitedareas. Examples of suitable adhesives used for such purpose include theacrylic emulsion E-1833BT manufactured by the Rohm & Haas Company,Philadelphia, Pa. and the acrylic emulsion WB 3805 manufactured by H. B.Fuller Company of St. Paul, Minn. The adhesives can be applied by any ofthe common techniques well known to those skilled in the art, forexample, the adhesive may be applied by spraying, by padding or by theuse of transfer rolls. The adhesive may be in the form of a uniformcontinuous layer, a patterned layer of adhesive, or an array of separatelines, spirals or spots of adhesive. The absorbent core 4 is preferablysecured in contacting relation to the secondary topsheet 3.

Referring again to FIGS. 1 and 2, it can be seen that absorbent core 4is positioned between secondary topsheet 3 and backsheet 5. Absorbentcore 4 provides the absorptive means for absorbing the bodily fluid.Absorbent core 4 is generally compressible, conformable andnon-irritating to the user's skin. It can comprise any material used inthe art for such purpose. Examples of such materials include multipleplies of creped cellulose wadding, fluffed cellulose fibres, wood pulpfibres also known as airfelt, textile fibres, a blend of fibres, a massor batt of fibres, a web of polymeric fibres, a blend of polyester andpolypropylene fibres, layers of cellulose tissue or layers of air laidtissue.

Preferably, the core comprises a mass or batt of fibres. While manytypes of fibres may be used, a preferred material is a batt of polyesterfibres. More preferably the core comprises cellulose tissue (63 g/m²)which forms a plurality of absorbent layers. FIG. 1 shows an absorbentcore 4 formed by one layer of cellulose tissue which has been folded asshown. FIG. 2 shows an absorbent core comprised of two layers of airlaid cellulose tissue 6 joined at their longitudinal edges with adhesive7.

Preferably, the odour control material disclosed herewith isincorporated into the absorbent core by known techniques. It may, forexample, be layered on or into the absorbent core or mixed with thefibres of the core. More preferably the odour control material 8, 20 islayered in accordance with the teaching of WO 94/01069 or TO 93A 001028as discussed previously between two layers of air laid cellulose tissueand the laminate is as shown in FIGS. 2 to 4 above. In particularpolyethylene powder, as thermoplastic material, is mixed with the odourcontrol material of the present invention, preferably zeolite, AGM andactivated carbon, the mixture is heated such that the polyethylene meltsand glues the laminate layers and components together. Adhesive linesare preferably also placed on the edges of the laminate as shown as 7,15 and 18 in the Figures to ensure that edges of the laminate sticktogether and any loose odour control material does not fall out of thelaminate.

As shown in FIGS. 3 and 4, pantiliner 9 comprises a liquid pervioustopsheet 10, an absorbent core 11, a liquid impervious backsheet 12,adhesive 13 which fastens the topsheet 10 to the backsheet 12, a layerof adhesive 21 which is secured to the backsheet 12 and which is coveredby removable release liner 22. The removable release liner 22 andassociated adhesive 21 may also be included in the pantiliners of FIGS.1 and 2. In FIG. 4 adhesive 23 in addition fastens the absorbent core 11to the portions of the topsheet 10 folded under the core 11. It is not,however, intended that the pantiliner should be limited to embodimentscomprising all such elements. Additional elements known to the skilledperson may also be included in the pantiliner.

Topsheet 10 is liquid permeable and, when pantiliner 9 is in use, is inclose proximity to the skin of the user. The topsheet 10 is as describedfor topsheet 2 in FIGS. 1 and 2.

The inner surface of topsheet 10 may be secured in contacting relationto absorbent core 11 as described for the pantiliner of FIGS. 1 and 2.

Preferably the topsheet 10 wraps around the core 11, as shown in FIGS. 3and 4, and is fastened by means of an adhesive 13 to backsheet 12.

Referring again to FIGS. 3 and 4, it can be seen that absorbent core 11is positioned between topsheet 10 and backsheet 12. Absorbent core 11 isas described for FIG. 2. FIG. 3 shows an absorbent core comprised of twolayers of air laid cellulose tissue 14 joined at their longitudinaledges with adhesive 15 and having a layer of cellulose tissue 16 therebeneath to form a three layered absorbent core. FIG. 4 shows two layersof air laid tissue 17 joined at their longitudinal edges with adhesive18 and having a layer of cellulose tissue 19 wrapped there around toform the third layer of the absorbent core.

Referring to FIGS. 1 to 4, the pantiliner is provided with a backsheet5, 12 which backsheet is impervious to liquids and, thus, prevents bodyfluid which may be expressed from absorbent core 4, 11 from soiling thebody or clothing of the user. Suitable materials are well known in theart, including woven and non-woven fabrics which have been treated torender them liquid repellent. Breathable or vapour pervious, liquidresistant materials, and those materials described in U.S. Pat. No.3,881,489 and U.S. Pat. No. 398,986 can also be used. Preferredmaterials are those materials that are fluid and vapour impervious,because they provide additional fluid strikethrough protection.Especially preferred materials include formed thermoplastic films. Oneespecially cuitable material is a polyethylene film having a thicknessof from about 0.075 mils to about 1.25 mils, with a 1.0 mil thicknesspolyethylene film being especially suitable. Preferably the backsheet 5,12 is polyethylene embossed film (24.4 g/m²).

The outer surface of backsheet 5, 12 may be coated with adhesive 21.Adhesive 21 provides a means for securing the pantiliner in the crotchportion of a panty. Any adhesive or glue used in the art for suchpurpose can be used herein, with pressure sensitive adhesives beingpreferred. Suitable adhesives are Century A-305-IV manufactured by theCentury Adhesives Corporation and Instant Lok 34-2823 manufactured bythe National Starch Company. Also, before pantiliner 1 or 9 is placed inuse, the pressure sensitive adhesive 21 should be covered with removablerelease liner 22 in order to keep adhesive 11 from drying out orsticking to a surface other than the crotch portion of the panty priorto use. Any commercially available release liners commonly used for suchpurposes can be utilized herein. Non-limiting examples of suitablerelease liners are BL 30 MG-A Silox El/O and BL 30 MG-A Silox 4 P/O bothof which are manufactured by the Akrosil Corporation. Preferably therelease liner is a silicon paper having a thickness of about 45 μm (43.5g/m²). Other means which are known in the art may be used to affix thepantiliner in the crotch portion of a panty. FIGS. 3 and 4 show anembodiment which comprises the adhesive 21 and removable release liner22.

The backsheet 5, 12 is preferably secured in the absorbent core 4, 11 bysecurement means (not shown), such as those well known in the art.

The invention will now be illustrated with reference to the exampleswherein the article for absorbing bodily fluids is a pantiliner or asanitary napkin. It will, of course, be appreciated that other absorbentarticles may also have the odour control material incorporated therein,the incorporation of the odour control material into the pant liner maybe achieved by other known methods and the odour control material may beany of those disclosed in the present specification.

EXAMPLES Incorporation of the Odour Control Material into a Pantiliner

The pantiliners used in the following examples were Always COMFORTPantiliners (Always is a Registered Trade Mark) as sold by the Procter &Gamble Company. Each pantiliner was opened at one end. The cellulosetissue sheet, which constitutes the absorbent core of the product wassubstituted with two layers of cellulose tissue that incorporate theodour control material homogeneously dispersed therein as shown in FIG.2. The whole pantiliner structure was then reconstituted.

Samples were prepared by the method as described above, which samplesincorporate the odour control material (OCM) as described hereintogether with AGM, AGM and activated carbon as illustrated in Table 1below wherein the total quantity of material, in grams, incorporatedinto each sample is shown.

The Odour Control Material used in the samples is the zeolite WessalithCS available from Degussa AG.

The AGM used in the samples is Drytech XZ 95890.01, available from DowEurope and the activated carbon is PCB type available from CalgonCompany Corporation (USA).

A commercially available Always Comfort (Always is a Registered TradeMark) pantiliner without modification was used as a reference (Blanksample 0).

                  TABLE 1                                                         ______________________________________                                               Quantity of material in g                                                       OCM                  Activated                                       Sample   (zeolite)     AGM    carbon                                          ______________________________________                                        1        0.40          0.30   --                                              2        0.22          0.30   0.18                                            ______________________________________                                    

Odour Control Test Protocol

Each test comprises four separate stages which may be summarised asfollows:

a) Consignment of the products.

b) Product return and preparation of the test samples.

c) Sniff-test.

d) Statistical analysis of the Data.

Each stage is described in more detail below.

a) Women were chosen who were known to have an odour control problem.Each of five women selected were given one product per test sampleindividually packaged in an anonymous bag. Every product was worn forseven hours.

b) The used product was placed into an aluminum tray, approximately 1 cmdeep, covered with a perforated aluminum sheet, in order to keep it outof view, and finally covered with another tray of the same type, whichwas kept thereon in inverted position up to the moment of thesniff-test.

c) The sniff-test was performed in a pre-ventilated room by fivegraders. Each grader had been preselected for their sensitivity to theunpleasant smells present in an absorbent article after use and theirability to grade the unpleasantness of the odour in a consistent manner.Every grader evaluated the odour of each series of five productsrepresenting each sample using a pleasantness scale which ranges from-10 (highest level of unpleasantness) to 5 (most pleasant). Thepleasantness values for each sample were obtained as a mean of 25observations (five grades, five products for each sample).

d) The results collected from the test were then analyzed by statisticalanalysis software (SAS). The data was processed in order to showstatistically significant differences between the treated and untreatedproducts.

This difference is shown in the tables by means of a letter (in the"Significant difference" column) near every mean value; results with thesame letter are not statistically significantly different.

Duncan's Multiple Range Test was used to form Multiple comparisons.Values of p<0.05 were considered statistically significant.

Example 1

Sample type 1 was tested together with the reference (blank sample 0).

It can be seen from the results collected in Table 2 and in FIG. 5 thatthe treated sample was statistically different from the reference and inparticular sample 1 having the odour control material as disclosedherein together with AGM, controls the odour when compared to thereference.

                  TABLE 2                                                         ______________________________________                                               Sample                                                                              Significant                                                             type  difference                                                       ______________________________________                                               1     B                                                                       0     C                                                                ______________________________________                                    

Example 2

The sample 2 was tested together with the reference (blank sample 0). Itcan be seen from Table 3 and FIG. 6 that the odour control materialtogether with AGM and activated carbon (sample 2) controls odour whencompared to the blank.

                  TABLE 3                                                         ______________________________________                                               Sample                                                                              Significant                                                             type  difference                                                       ______________________________________                                               2     A                                                                       0     C                                                                ______________________________________                                    

Comparative Example A

Sample 1 from Example 1 was compared to the following samples.

Sample 4

0.30 g AGM+0.40 g zeolite Abscents

Sample 5

0.30 g AGM+0.40 g zeolite Y.

The zeolite Abscents is available from UOP (USA) and has a particle sizeof 5 μm and is as disclosed in U.S. Pat. No. 4,826,497. The AGM is thesame as that mentioned previously. Zeolite Y is CBV 400 Zeolite HYavailable from PQ Corporation (USA).

The reference sample is as before. The results are shown in Table 4 andin FIG. 5.

                  TABLE 4                                                         ______________________________________                                                     Significant                                                             Sample                                                                              difference                                                       ______________________________________                                               1     B                                                                       4     B                                                                       5     C                                                                       0     C                                                                ______________________________________                                    

In FIG. 5 the scale on the Y axis, namely the unpleasantness grade, is anegative scale showing a maximum unpleasantness of -3.5 for Sample 0.

It can be seen that the odour control material with AGM (sample 1) hasthe same odour control capacity of Abscents and AGM but is not dusty andis thus much easier to handle than the conventionally used zeolites. Inaddition the odour control material as disclosed herein is significantlycheaper than the conventionally used Abscents zeolite. The odour controlmaterial as disclosed herein with AGM (sample 1) is surprisinglysignificantly better than a conventionally used zeolite Y.

Comparative Example B

Sample 2 from Example 2 is compared to the following samples.

Sample 6

0.30 g AGM+0.22 zeolite Y and 0.18 g activated carbon.

Sample 7

0.30 g AGM+0.45 g agglomerate zeolite Y/activated carbon.

Zeolite Y is the same as that used in comparative Example A. Theactivated carbon was as mentioned previously. The agglomerate of zeoliteY and activated carbon is as disclosed in WO 91/12030.

The sample reference is as before.

The results are shown in Table 5 and FIG. 6.

                  TABLE 5                                                         ______________________________________                                                     Significant                                                             Sample                                                                              difference                                                       ______________________________________                                               2     A                                                                       6     B                                                                       7     B                                                                       0     C                                                                ______________________________________                                    

In FIG. 6 the scale on the Y axis, namely the unpleasantness grade, is anegative scale showing a maximum unpleasantness of -3.5.

It was surprisingly found that the Sample 2, of the present invention,controlled odour significantly better than either Sample 6 or 7.

Similar results were obtained when the odour control material wasincorporated into a sanitary napkin in the following manner.

Incorporation of the OCM into a Sanitary Napkin

The samples were obtained from commercially available Lines Liberty Ideasanitary napkins as sold by Fater SpA.

Each napkin is opened by cutting the wrap around perforated coverstockat its bottom face approximately along a longitudinal edge of therelease paper which covers the external adhesive layer.

The side of the absorbent fibrous core is then exposed by slightlyshifting the water impermeable plastic bottom layer and, subsequently,the fibrous core is split into two halves, each having approximately thesame thickness, along a plane which is parallel to the plane of thenapkin itself.

The odour control material is homogeneously dispersed between these twofibrous layers which are then joined together to reconstitute theabsorbent core.

The water impermeable inner backsheet is then put back into its originalposition and the wrap around perforated coverstock is sealed along thecut by means of e.g. a double sided adhesive tape.

The test protocol is substantially the same as previously described forthe pantiliners, with the exception that the mean values of theunpleasantness obtained from the 25 observations for each sample havebeen corrected with a statistical technique called "covariance analysis"to take into account the fact that there was not a fixed wearing timefor the sanitary napkins.

The results obtained are as follows:

Example 3

Sample type 3 and a reference blank sample 0 were tested in order toshow the odour removing capability of the odour control material asdisclosed herein.

Sample 3

0.4 g OCM

The pleasantness grade values show statistically significant differencesbetween the product with the odour control material and the reference(blank sample 0) thus showing effective odour control by sample 3.

                  TABLE 6                                                         ______________________________________                                               Sample                                                                              Significant                                                             type  difference                                                       ______________________________________                                               3     D                                                                       0     C                                                                ______________________________________                                    

Comparative Example C

Sample 3 from Example 3 was compared to the following Sample.

Sample 8

1 g zeolite Abscents (Abscents is a registered trade mark)

Abscents is available from UOP (USA) has a particle size of 5 μm and isas disclosed in U.S. Pat. No. 4,826,497.

The reference sample is as before. The results are shown in Table 7 andalso in FIG. 7

                  TABLE 7                                                         ______________________________________                                                     Significant                                                             Sample                                                                              difference                                                       ______________________________________                                               3     D                                                                       8     D                                                                       0     C                                                                ______________________________________                                    

In FIG. 7 the scale on the Y axis, namely the unpleasantness grade, is anegative scale showing a maximum unpleasantness of -4.

It is shown that the odour control material used in the presentinvention has the same odour control ability of a conventionally usedzeolite however the odour control material used in the present inventionis not dusty and is thus much easier to handle than the conventionallyused zeolite and is also much cheaper.

A further material which controls odour in accordance with thisinvention is shown in Example 4.

Example 4

0.15 g OCM(zeolite)+0.20 g AGM+0.12 g activated carbon

wherein the zeolite, AGM and activated carbon are those as used for thesamples shown in Table 1.

What is claimed is:
 1. An absorbent article having an odour controlmaterial for decreasing bodily odour associated with bodily fluids, theodour control material consisting of zeolite particles having an averageparticle size of at least 200 μm.
 2. An absorbent article as claimed inclaim 1 wherein the average particle size of the zeolite is from about200 μm to about 500 μm.
 3. An absorbent article as claimed in claim 1wherein less than 10% by weight of the zeolite particles have a particlesize less than 100 μm.
 4. An absorbent article as claimed in claim 1wherein the zeolite has a pore diameter of from about 0.30 nm to about0.55 nm.
 5. An absorbent article as claimed in claim 1 wherein thezeolite is granulated with a binder.
 6. An absorbent article as claimedin claim 5 wherein the zeolite is granulated with sodium sulphate andcarboxy methyl cellulose.
 7. An absorbent article as claimed in claim 1wherein the zeolite has a framework ratio of silicon dioxide to aluminumoxide of not more than 4:1.
 8. An absorbent article as claimed in claim1 wherein the zeolite is zeolite A.
 9. An absorbent article as claimedin claim 1 wherein the zeolite comprises a cation, and the cation isselected from the group consisting of sodium ions, potassium ions,ammonium ions, alkylammonium ions, and heavy metal ions.
 10. Anabsorbent article as claimed in claim 1 wherein the odour controlmaterial comprises from about 2 to about 70% of the total weight of theabsorbent article.
 11. An absorbent article as claimed in claim 9wherein the cation is a sodium ion.
 12. A composition as claimed inclaim 11 wherein the cation is a sodium ion.